1. Field of the Invention
This invention relates to power sources, and particularly to an electrical power source giving rise to a current through the ionization of a doped diamond or other substrate by energetic alpha particles.
2. Description of the Related Art
While most people are familiar with electrical power in their homes and office as being available through an electrical socket or junction, all electrical power must be generated in some manner. Industrial-sized processes in plants allow the generation of megawatts of electricity for distribution over an electric grid powering cities and towns as well as major industrial facilities. However, there is a need for electrical power generation in environments that are otherwise isolated from large scale or other electric power grids. Such environments include orbital and deep space as well as open water and deep ocean exploration and activities.
Prior attempts in the art to supply electrical power for circuitry and equipment include the construction of radioisotope thermoelectric generators (RTGs) as well as lithium batteries, rechargeable batteries, and solar cell panels. Each of these forms of power generation has their advantages and disadvantages. They are also well-documented in the art.
In some circumstances, these prior art generators are not generally miniaturized in order to provide low-power sources. Additionally, the efficiencies of these generators leaves room for improvement as they are generally not very efficient and do not lead themselves to use in either low temperature or high temperature environments.
Consequently, there is significant room for improvement with respect to low-energy power sources provided on a miniaturized or other basis for space and ocean exploration missions. The present invention provides an alternative to prior art devices as well as advancing the art by delivering more efficient power source that is self contained and easily incorporated into advanced and highly-optimized equipment.
In view of the foregoing disadvantages inherent in the known types of power sources now present in the prior art, the present invention provides a very high efficiency, miniaturized, and long-lived power source wherein the same can be utilized for supplying electrical power where it would be unavailable otherwise.
The general purpose of the present invention, which will be described subsequently in greater detail, is to provide an very high efficiency, miniaturized, and long-lived power source which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art power sources, either alone or in any combination thereof.
The present invention uses the kinetic energy of xcex1-particles emitted during radioactive decay. Alpha particles are the nuclei of helium atoms that are emitted and travel without the usual accompanying electrons present in un-ionized helium atoms. In comparison to beta particles (electrons) and gamma rays (high energy electromagnetic radiation), xcex1-particles are massive with kinetic energy that is readily-convertible to electrical energy under the proper circumstances. The present invention provides such circumstances in order to convert the comparatively large fraction of available kinetic energy to electrical energy. With the use of radioactive isotopes, such a power source can be used in environments that are isolated from other power sources.
A PN structure is provided in the form of N-doped diamond film and P-doped diamond film. The N- and P-doped diamond films are doped at low densities to maximize the depletion region for high efficiency operation. In one embodiment, curium 244 is used to provide xcex1-particles. The kinetic energy of the xcex1-particles generates free electron and hole pairs. A hole represents the absence of an electron in a covalent bond. Due to the built-in electric field, electrons and holes are separated and are forced to flow in opposite directions, creating a current which then can be used to power devices, including electronics.
Ohmic contacts are used to collect current from the PN junction. Additionally, the entire power generator may be situated atop a diamond substrate.
Diamond is the hardest substance known and generally has the same covalent electron and similar conduction properties as silicon. The crystalline form of carbon operates electronically in a manner very similar to that as crystalline silicon. However, diamond provides hardened substrates that resist degradation from radiation-induced defects and displacement damage without deteriorating. Additionally, the power source of the present invention can operate in both very cold and very hot environments without losing the ability to generate power.
Devices can be connected in series to elevate the voltage and in parallel to elevate the current.
Alternatively, an N-doped silicon substrate may be used for the N-type diamond layer.
The present invention provides a self-contained power source that may be used for powering many different devices not the least of which is electrical circuitry. Such a supply of power can be providing power to an otherwise power-isolated environment such as deep space, deep ocean, and other environments. The construction of the device is generally straightforward and available such that manufacture could occur without significant obstacles. In conjunction with curium-244 radioisotope, a useful life of approximately 18 years corresponding to the half-life of curium-244 is expected. Conversion of the approximately 5.8 mega electron volt (MeV) xcex1-particles may occur with a significant to high degree of efficiency to electrical energy. Additionally, the diamond-based device of the present invention lends itself to use in hostile environments requiring hardened or stable sources.
It is an object of the present invention to provide a power source that is self-contained.
It is another object of the present invention to provide a power source that is long-lived.
It is yet another object of the present invention to provide a power source that is efficient.
It is yet another object of the present invention to provide a power source that is small and/or subject to miniaturization.
It is another object of the present invention to provide a power source that lends itself to use in hostile or isolated environments.
It is yet another object of the present invention to provide a power source that is reliable.
It is another object of the present invention to provide a power source that is readily manufactured.
These and other objects and advantages of the present invention will be apparent from a review of the following specification and accompanying drawings.